Abstract

Key message

Both water availability and temperature modulate the growth ofHymenaea courbarilon karst in Central Brazil. There is evidence of teleconnections between South Atlantic SST and tree growth.

Abstract

Tropical dry forests have low annual precipitation and long dry seasons. Water availability, the main restrictive growth factor, becomes more pronounced in the shallow and highly porous soil of karst regions. Understanding how climate regulates tree growth in stressful environments is essential for predicting climate change impacts on trees. The aim of this study was to build a tree-ring chronology of Hymenaea courbaril growing in a karst dry forest and evaluate how local climate and teleconnections modulate its growth. To accomplish this, increment cores of 19 individuals were sampled in Terra Ronca State Park located in Goiás State, Central Brazil. After surface polishing, tree rings were identified, measured, dated, and a tree-ring chronology was built with 17 individuals. The chronology was correlated with local and regional climate data (temperature, precipitation, air humidity). We also tested teleconnections with sea surface temperature (SST) of the Equatorial Pacific and South Atlantic. Results show that air humidity, precipitation amount, and its distribution during the transition period between dry and wet seasons positively regulate this species growth. On the other hand, growth is negatively correlated with temperature during the middle of the previous year’s dry season. Additionally, growth is negatively correlated with SST of the Southern Atlantic, but not with Equatorial Pacific. These relationships between climate and growth indicate that predicted increases in regional temperature and decreases in water availability may limit the growth of H. courbaril in karst dry forests.

Notes

Acknowledgments

Authors thank Paula Jardim and Viviane Jono for helping with the wood material processing, Jean-Sébastien Moquet and Ramiro Hilario dos Santos for helping with the field work, Francisco Willian Cruz for inviting our team to work at Terra Ronca State Park, and Eric Rezende Kolailat and the SEMAHR Goiás for providing the work license, and the anonymous reviewers for all valuable input in the manuscript. Authors also thank FAPESP (São Paulo Research Foundation 12/50457-4) and CNPq (National Council for Scientific and Technological Development 478503/2009-1, 142706/2011-6, 307041/2014-0) for funding.